Swimming pools typically have a polymeric liner along their insider surface that serves several functions including, without limitation, providing a water impermeable surface, providing an aesthetically pleasing cover to the concrete or metal pool walls/floor and providing a pleasing to the touch contact surface with those enjoying the pool. However, given the nature of the materials used in the construction of pool liners, they must be replaced every few years due to wear-and-tear on the liner. Before a pool liner can be replaced, an accurate measurement of the perimeter and depth of the pool must be made and, as discussed below, the prior art method of measuring the perimeter of the pool is time consuming and error prone leading to costly waste for both the consumer, the pool liner installers and the pool liner manufacturers. According, it is desirable to have an improved method and apparatus for the measurement of the perimeter of a swimming pool before ordering a replacement pool liner. An improved method and apparatus are provided herein.
As shown in FIG. 1, the prior art method and apparatus used to measure the perimeter 50 of a pool 10 for a replacement pool liner 40 involves “A-B point-to-point-triangulation” wherein two reference points 20A and 20B are placed on the ground with a straight line between them (that does not intersect the perimeter 50 of the pool 10) and a series of measurements are made to a plurality of points X along the perimeter 50. The size and shape of the pool 10 dictate how many points X must be placed along the perimeter 50 to obtain an accurate measurement. As shown in FIG. 1, the points X must be spaced closer together in curved regions of the perimeter 50 than straighter regions of the perimeter 50 (compare the spacing of points X17-X27 to that of X1-X5) in order to obtain accurate measurements of the perimeter of the curved region of the perimeter 50. Additionally, at times, the size and shape of the entrance to the pool 10, such as stairs 30, must be taken into account during the measurement process. Once a satisfactory number of points X have been placed along the perimeter 50, by the use of a tape measure or other hand held measuring device, a series of measurements from each point X to each reference point 20A, 20B must be made. As shown by example in Fig, 1, the distance from point X1 to reference point 20A and to reference point 20B must be determined by measuring the length of the line AX1 and BX1 respectively. Likewise, a similar calculation must be made for every point X along the perimeter 50. Other exemplary lines of measurement are shown in FIG. 1 including AX3, BX3, AX17, BX17, AX27 and BX27. As expected, the errors and inefficacies inserted in making this many measurements can be great. These measurements then must be transferred to the pool liner manufacturer who then fabricates the pool liner 40. At times, the errors generating in manually measuring the perimeter 50 are so great that the pool liner 40 cannot be fitted to the pool 10. Given applicant's experience in the pool liner industry, the errors associated with the prior art method of measuring the perimeter 50 of the pool 10 could exceed 40 million dollars per year.